Holmes Township was a civil township in Mackinac County in the U.S. state of Michigan. Organized on April 12, 1827, Holmes included parts of Michigan's upper and lower peninsulas within the original county of Michilimackinac. The county and township both became smaller over time, until 1895 when Holmes consisted of only Mackinac Island and Round Island. Holmes was incorporated into the City of Mackinac Island effective March 20, 1900.

Holmes Township was created with the following legal description:

Commencing at the intersection of the Cheboigun river, with the parallel of north latitude 44 degrees 30 minutes, and running west along said parallel, until it strikes Lake Michigan, thence due north until it intersects the parallel of north latitude 46 degrees, thence east along said parallel until it would intersect a line due north from the place of beginning.

Interpreting this description today is problematic because there is no intersection between the headwaters of the Cheboygan River and the line of 44.5 degrees north latitude. Better maps of northern Michigan rivers were available by 1836, but this discrepancy leaves the original eastern bound of Holmes indeterminate.